I see no problem if their is a plate underneath the airstone. If the plate is large enough it should keep the air from scouring the bottom. Keep in mind the column flow of air is going up if the bottom of your airstone(s) is pointed in the right direction.

If you're concerned about the stone how about a membrane diffuser that only pushes air up? You can also elivate your stone by various means. Some folk build PVC stands with three way connectors and PVC to elevate their stone up of the bottom about a foot. I have done this.

If pigs could fly bacon would be harder to come by and there would be a lot of damaged trees.